3.2.9. RUBBER CLOSURES FOR CONTAINERS FOR …

1 RUBBER CLOSURES for containersEUROPEAN PHARMACOPOEIA :30209corrected RUBBER CLOSURES FORCONTAINERS FOR AQUEOUSPARENTERAL PREPARATIONS,FOR POWDERS AND FORFREEZE-DRIED POWDERSR ubber CLOSURES for CONTAINERS for aqueous parenteralpreparations for powders and for freeze-dried powders aremade of materials obtained by vulcanisation (cross-linking)of macromolecular organic substances (elastomers), withappropriate additives. The specification also applies toclosures for CONTAINERS for powders and freeze-driedproducts to be dissolved in water immediately before specification does not apply to CLOSURES made fromsilicone elastomer (which are dealt with Siliconeelastomer for CLOSURES and tubing), to laminated closuresor to lacquered CLOSURES .

2 The elastomers are producedfrom natural or synthetic substances by polymerisation,polyaddition or polycondensation. The nature of theprincipal components and of the various additives (forexample vulcanisers, accelerators, stabilisers, pigments)depends on the properties required for the finished CLOSURES may be classified in 2 types: type I closuresare those which meet the strictest requirements and whichare to be preferred; type II CLOSURES are those which, havingmechanical properties suitable for special uses (for example,multiple piercing), cannot meet requirements as severeas those for the first category because of their CLOSURES chosen for use with a particular preparationare such that.

3 The components of the preparation in contact with theclosure are not adsorbed onto the surface of the closureand do not migrate into or through the closure to anextent sufficient to affect the preparation adversely, the closure does not yield to the preparation substancesin quantities sufficient to affect its stability or to presenta risk of CLOSURES are compatible with the preparation for whichthey are used throughout its period of manufacturer of the preparation must obtain from thesupplier an assurance that the composition of the closuredoes not vary and that it is identical to that of the closureused during compatibility testing.

4 When the supplier informsthe manufacturer of the preparation of changes in thecomposition, compatibility testing must be repeated, totallyor partly, depending on the nature of the CLOSURES are washed and may be sterilised before CLOSURES are elastic; they are translucent or opaqueand have no characteristic colour, the latter dependingon the additives used. They are practically insoluble intetrahydrofuran, in which, however, a considerable reversibleswelling may occur. They are homogeneous and practicallyfree from flash and adventitious materials (for examplefibres, foreign particles, waste RUBBER ).

5 Identification of the type of RUBBER used for the CLOSURES isnot within the scope of this specification. The identificationtest given below distinguishes elastomer and non-elastomerclosures but does not differentiate the various types ofrubber. Other identity tests may be carried out with the aimof detecting differences in a batch compared to the closuresused for compatibility testing. One or more of the followinganalytical methods may be applied for this purpose:determination of relative density, determination ofsulphated ash, determination of sulphur content, thin-layerchromatography carried out on an extract, ultravioletabsorption spectrophotometry of an extract, infraredabsorption spectrophotometry of a The elasticity is such that a strip of material with across-section of 1 mm2to 5 mm2can be stretched byhand to at least twice its original length.

6 Having beenstretched to twice its length for l min, it contracts to lessthan times its original length within 30 Heat 1 g to 2 g in a heat-resistant test-tube over an openflametodrythesampleandcontinueheatin guntilpyrolysate vapours are condensed near the top edgeof the test-tube. Deposit a few drops of the pyrolysateon a potassium bromide disc and examine by infraredabsorption spectrophotometry ( ), comparing withthe spectrum obtained with the type The total ash ( )iswithin 10percentoftheresultobtained with the type samples to be analysed may be washed and sterilisedbefore S.

7 Introduce a number of uncut closurescorresponding to a surface area of about 100 cm2in asuitable glass container , cover withwater for injections R,boil for 5 min and rinse 5 times with coldwater forinjections (glass type I, ), add 200 ml ofwater forinjections Rand weigh. Cover the mouth of the flask witha borosilicate-glass beaker. Heat in an autoclave so that atemperature of 121 2 C is reached within 20 min to 30 minand maintain at this temperature for 30 min. Cool to roomtemperature over about 30 min. Make up to the originalmass withwater for injections the solution from the RUBBER by decantation.

8 Shakesolution S before each for injections of solution. Solution S is not more opalescentthan reference suspension II for type I CLOSURES and is notmore opalescent than reference suspension III for type IIclosures ( ). Solution S is not more intensely colouredthan reference solution GY5( , Method II).Acidity or blue solution M sodium hydroxideor ml M hydrochloricacidis required to obtain either a blue or a yellow colour, out the test within 5 h of preparationof solution solution S on a membrane filter havingapproximately m pores rejecting the first few millilitresof filtrate.

9 Measure the absorbance ( )ofthefiltrateatwavelengths from 220 nm to 360 nm using the blank (seesolution S) as compensation liquid. At these wavelengths,the absorbance does not exceed for type I CLOSURES or type II CLOSURES . If necessary, dilute the filtrate beforemeasurement of the absorbance and correct the result forthe out the test within 4 h ofpreparation of solution sulphuric acid Rand ml M386 See the information section on general monographs (cover pages)EUROPEAN PHARMACOPOEIA RUBBER CLOSURES for containerspotassium iodide Rand titrate immediately Msodium thiosulphate, using ml ofstarch solution Rasindicator.

10 Carry out a titration using ml of the ( ): maximum 2 5 ml of solution S to 14 ml withwater with limit test zinc: maximum of g of extractable Zn permillilitre of solution absorption spectrophotometry ( , Method I).Test solution. Dilute ml of solution S to 100 ml M hydrochloric solutions. Prepare the reference solutions usingzinc standard solution (10 ppm Zn) Rdiluted Mhydrochloric heavy metals( ): maximum 2 S complies with limit test A. Prepare the standardusinglead standard solution (2 ppm Pb) on evaporation.